The Macromolecular Structure Shared Resource (MSSR) is comprised of the X-ray crystallography (X-ray) and the Nuclear Magnetic Resonance (NMR) laboratories. X-ray crystallography and NMR are highly complementary methods for elucidating three-dimensional structures and for studying macromolecular interactions. Together, they provide Cancer Center members with comprehensive methodologies to understand how cancer-related biological macromolecules function in normal and diseased states at the molecular level. Cancer Center investigators will be advised and assisted in utilizing these sophisticated technologies to determine structures of cancer-related biological macromolecules and to investigate their interacfions with other macromolecules and with potential therapeutic agents by the Directors of the X-ray and NMR laboratories, P. John Hart, PhD and Andrew P. Hinck, PhD, respectively. The X-ray component of the MSSR includes an Art Robbins crystallization robot and two state-of-the-art Rigaku-MSSR X-ray data collecfion systems. The instrumentation provides full capabilities for conducting all modern X-ray diffraction experiments and is suitable for obtaining high quality three-dimensional structures of proteins, nucleic acids and their complexes. The NMR component of the MSSR includes state-of-the-art Bruker spectrometers equipped with high sensitivity cryoprobes operating at 500, 600, and 700 MHz. The instrumentafion provides full capabilities for conducting modern NMR experiments with N, C, and H labeled macromolecules and is suitable for obtaining three-dimensional solution structures and investigating interactions with other macromolecules and potential therapeutic agents. The MSSR is made accessible to the broader Cancer Center Membership by PhD-trained technical managers, Alex Taylor, PhD, and Udayar llangovan, PhD, for the X-ray and NMR laboratories, respectively, who provide guidance at each step in the process, from sample preparation to interpretation and presentation of results. The MSSR provides a comprehensive array of methodologies with which to visualize and functionally characterize cancer-related biological macromolecules.